Examples of photoelectric conversion devices used for photovoltaic power generation and the like include chalcopyrite-based photoelectric conversion devices such as copper indium selenide type (CIS type) and copper indium gallium selenide type (CIGS type) ones.
The chalcopyrite-based photoelectric conversion device typically includes a photoelectric conversion layer comprised of a chalcopyrite-based compound such as copper indium diselenide as a light-absorbing layer and a compound semiconductor comprised of cadmium sulfide or the like as a buffer layer.
An example of the method for manufacturing a CIGS cell being one of chalcopyrite-based photoelectric conversion devices is as follows. First, a metal thin film comprised of molybdenum or the like is formed on a glass substrate to form a back electrode, and then, a separating groove for separating the back electrode in strip shapes is formed. Then, a CIGS layer serving as a photoelectric conversion layer and a buffer layer are formed on the substrate and the back electrode, and subsequently, a separating groove for separating the buffer layer and the CIGS layer is formed at a position proximate to the separating groove of the back electrode. Then, an electrode comprised of a transparent conductive film is produced on the buffer layer, and a grid electrode is printed and fired thereon. After that, a separating groove for separating the electrode, the buffer layer, and the CIGS layer is formed, to thereby form CIGS cells (for example, see Patent Document 1: Japanese Patent Application Laid-Open No. 2002-373995).
The separating groove of the back electrode on the substrate as described above is typically formed by laser processing (for example, see Patent Document 2: Japanese Patent Application Laid-Open No. 2002-43605).